Strapping machine

ABSTRACT

This machine straps a package with heat sealable plastic strapping. The strap is fed by geared feed and tension wheels around a yoke and against a stop. The strap is gripped against a side-retractable anvil on opposite sides of a vertically moving platen and knife assembly, while straddling a retractable tongue. A heated blade replaces the tongue whereupon the platen squeezes the heated joint and cuts the strap. The anvil and tongue are withdrawn for removal of the strapped package. The platen, tongue, anvil and sealing blade are controlled by a set of cams on a linear actuator.

United States Patent 91 Goodley Sept. 18, 1973 STRAPPING MACHINE [75] Inventor: George F. Goodley, Media, Pa. [73] Assignee: FMC Corporation, San Jose, Calif.

[22] Filed: Nov. 15, 1971 [21] Appl. No.: 198,862

Bartlett 100/33 PB Primary Examiner-Billy J. Wilhite Attorney-F. W. Anderson et al.

[57] ABSTRACT This machine straps a package with heat sealable plastic strapping. The strap is fed by geared feed and tension wheels around a yoke and against a stop. The strap is gripped against a side'retractable anvil on opposite sides of a vertically moving platen and knife assembly, while straddling a retractable tongue. A heated blade replaces the tongue whereupon the platen squeezes the heated joint and cuts the strap. The anvil and tongue are withdrawn for removal of the strapped package. The platen, tongue, anvil and sealing blade are controlled by a set of cams on a linear actuator.

12 Claims, 61 Drawing Figures FOOT VALVE, FV

PATENTEDSEH 8 ms SREH 02 Bf 28 NWEA N LUHGH 0w .NN.

||||| NmN 2 55: I um- F.

PATENTED SEP 1 8 I975 sum a: nr 23 PATENTEBSEP? 8 ms 3,759,169

SREH 05 0F 28 F'I E] E TONGUEZ4- ANVIUB 2 z BLADE.Z8

pmamensw 3.159.169

SHEET [17 HF 28 PLATEN CAMJ'IS m e TONGUE-ANVIL L'! CAM ,|1e

a 23c BLADE ARM CAM 2040- HOLD our K was wen HOLD OUT FII3 12 TIC-L113 PATENTED 81975 3. 759 159 SHEET 10 0F 28 FII3 1El (SEE FIG. 33)

ANVIL, l8 FRONT GRIPPER STOP,i9 zwze 9;. OPEN 3o FEEDING 5V CLOSED (SEE FIG. 34)

l FIE 2I'J STOP FEED OVER l8) STOP||9 s 30 CLOSED REVERSE STRAP LIMIT VALVE S V OPEN 32.0PEN 2.6

FIE: 2 [1A PATENTED 3. 759 .159

SEMI 11 0F 28 FIB 2l 5 (SEE FIG. 34)

STRAP LIMIT WITHDRAWS LOOP 5V FIE: 22

(SEE FIG. 35)

PATEN TED SEP 1 8 I973 sum 12 or 2 T m T s TENSION TI[3 2EI (SEE FIG. 36)

Ill

"IHIIIH G4 TENSION LIMIT/ VALVE -rv TF'I 'B 241 (SEE FIG. 37)

S TIGHTENED TENSION LIMIT VA V STOPS MOTOR STARTS CAM PI'XTENIFD 81975 3.759 169 SHE 1; UP 28 F I B 2 5 (SEE FIG. 37) .1

iF-IB 2E;A

TONGUE 1'? 8 ADVANCING BLADE Aogmcso VALVE CLOSED J 8 {$0 T 6 2 E FULLY I B =E ADVANCED 24 2e RETRACTING Pmzmlzusw 3.759.169

sum 15 0f 28 "1 FIEI Z'7 V2.8 PRESSURE \Z6 FIB 2'7A 7, TONGUE FULLY 1'16 (1 WITHDRAWN \18c I18 Q APPLYING PRESSURE ADVANCING RETRACTING BLADE \800 :52

CUT (SEE FIG. 37)

CLOSED T I E- z 7 B Mo 28 24 749 rfizme WITHDRAWN IZO'" PATENTED SEP 1 8 I975 SBEEI 15 II 28 PLATEN 25 T11 [-lZElA T'IE ZIEI CLOSED PLATEN FULLY RAISED mad gag,

\ao |5Z- lwdl i i HOLD OUT i504 j b -8 J 

1. Article strapping apparatus of the type wherein reversible, power driven strap transport wheel means feeds the strap through an article receiving yoke, and beneath an anvil, the end of the strap is gripped against a retractable anvil, the transport wheel means is reversed to tension the strap about an article, and the bight of the strap is gripped against the anvil, a heat seal blade is advanced between the end and the bight of the strap, and the heated zone of the strap is pressure sealed by a platen upon blade withdrawal; the improvement wherein a retractable tongue separates the end and the bight of the strap, cam means for retracting the tongue before entry of said blade, cam means for causing said platen to squeeze the heated strap portions, means for retracting said blade, and cam means for thereafter retracting the anvil from between the strap and the article.
 2. The apparatus of claim 1, comprising cam means for advancing and retracting said blade and for operating said platen.
 3. The apparatus of claim 2, wherein said cam means comprises a plurality of individual cams reciprocated by a linear actuator.
 4. The apparatus of claim 3, comprising means for sensing strap tension when the article is strapped, and thereupon initiating motion of said linear actuator in one direction so as to retract said tongue, advance said blade and advance said platen.
 5. The apparatus of claim 4, comprising time delay means for allowing said linear actuator to dwell after completion of its motion in said one direction for cooling the sealed joint and thereafter initiating return motion of said actuator.
 6. The apparatus of claim 3, wherein said cam means for operating the tongue and the anvil comprises a single cam operated by said linear actuator, and a T-shaped bell crank having its leg engaging said cam for pivoting the bell crank, one end of its crossbar retracting said tongue wherein the bell crank is pivoted in one direction, the other end of its crossbar retracting said anvil when the bell crank is pivoted in the other direction.
 7. The apparatus of claim 1, wherein said tongue and anvil are pivotally mounted on the same side of of the strap, spring means for advancing the tongue and anvil to the strap, spring means for advancing the tongue and anvil to the strap, and abutment means between the tongue and anvil so that retraction of the anvil holds the tongue retracted.
 8. Article strapping apparatus of the type wherein reversible, power driven strap transport wheel means feeds the strap through an article receiving yoke, the end of the strap is gripped against an anvil, the transport wheel means is reversed to tension the strap about an article, the bight of the strap is gripped against the anvil, a heat seal blade enters between the end and the bight of the strap, and a raisable platen squeezes the heated zones of the strap upon blade withdrawal; the improvement comprising a linear actuator, cam means connected to said actuator for advancing and retracting the heat seal blade and for raising said platen upon advance of said linear actuator, said cam means lowering said platen upon retraction of said actuator, and means for holding said heat seal blade retracted upon retraction of said actuator.
 9. The apparatus of claim 8, comprising time delay means for momentarily maintaining said linear actuator in its advanced position to accommodate cooling of the strap joint, and means for thereafter retracting said linear actuator.
 10. The apparatus of claim 8, wherein cam means for the heat seal blade has a notch for advancing the blade, said means for holding the heat seal blade retracted upon retraction of the linear actuator comprises a hold out for blanking out the notch in said heat seal blade cam means.
 11. Article strapping apparatus of the type wherein reversible, power driven strap transport wheel means feeds the strap through an article receiving yoke, and beneath an anvil, the feed is stopped, the end of the Strap is gripped by a front gripper against an anvil, the transport wheel means is reversed to tension the strap about an article, and the bight of the grip is gripped by a rear gripper against the anvil, a retractable tongue between said grippers, a heat seal blade enters between the end and the bight of the strap as the tongue is retracted, and the heated zone of the strap is pressure sealed upon blade withdrawal; the improvement comprising a linear actuator, cam means on said actuator for retracting the tongue and advancing and retracting said blade when the actuator is advanced, cam means for squeezing the heated strap portions, strap tension controlled means for advancing said actuator after the strap has been tensioned around the article, actuator control means for retracting said actuator after the sealed joint has cooled to hold said blade retracted and advance said tongue, and feed control means operated on full retraction of said actuator for re-initiating strap feed by said transport wheel means.
 12. The apparatus of claim 10, wherein said actuator control means comprises a timer, control means for starting timing upon advance of said actuator, said timer timing out after providing strap joint cooling time and thereupon initiating retraction of said actuator. 